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I am trying to setup an RSA Authentication only SSH/SFTP server. The SSH will be used primarily for RDC. Everything works just fine if I use password authentication.

I am using Putty Key Generator to create he keys and I have pasted the key into authorized_keys file and restarted the OpenSSH server. I am using FileZilla to test the SFTP connection as that is the most important. For my tests I have created the keys without password correction.

It will not work with a standard SSH connection either. It says "Server refused our key". I have recreated the key twice double checking with a guide on google, and I am pretty sure I did it correctly.

I load the key file into FileZilla under settings/SFTP and try to connect and I get the following error: Disconnected: No supported authentication methods available.

I have been playing with the different settings all night and I cannot figure it out. Here is my sshd_config file:

# $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $

# This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options change a
# default value.

#Port 22
#AddressFamily any
#ListenAddress ::

# Disable legacy (protocol version 1) support in the server for new
# installations. In future the default will change to require explicit
# activation of protocol 1
Protocol 2

# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 1024

# Logging
# obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
PermitRootLogin no
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication no
PermitEmptyPasswords no

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

# Set this to 'yes' to enable PAM authentication, account processing, 
# and session processing. If this is enabled, PAM authentication will 
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM no
share|improve this question
I might look again at this section: # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts RhostsRSAAuthentication no It might be a bug...I would also make sure that the RSA key is not for a root login. – hbdgaf Jan 18 '11 at 16:26
Thanks for the comment. I checked that out, and made sure it was all commented, but it made no difference. The RSA key is not for root login. – Siriss Jan 20 '11 at 3:22
up vote 1 down vote accepted

Putty Key Generator uses its own format of the key. You should export the key to OpenSSH format but even that did not work for me until I manually edited the hash to be all in a single line.

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